Filter for phase separation

ABSTRACT

The invention relates to a filter for fluids displays a number of film elements ( 1 ) stacked on top of each other, showing central perforations ( 2 ) aligned with each other. In order to simplify the manufacturing, the film elements ( 1 ) of neighboring stacks ( 4 ) on the same level are connected to each other by connecting fillets. Hence the filter elements ( 1 ) form an inherently stable matrix which can be easily stacked.

The invention concerns a filter for phase separation according to thegeneric term of claim 1.

The separation can take place especially between the solid-liquid aswell as solid-gas phases, but in theory even between different oridentical phase combinations.

These types of so-called marginal column filters are employed inparticular in the cleaning of polluted cooling lubricants. Generallyso-called filter cartridges are utilized. The basic theory is that filmrings in paper, metal plastic or ceramics are fixed on tube-shaped metalcore having, for example, a square cross-section. The fluid to becleaned flows from the outside through the intermediate areas betweenthe layers, whereby the particles stick to the outside and form theso-called filter cake. The filtered liquid then flows into the spacebetween the inner sheath surface of the film stack and the outer sheathsurface of the tube to one end of the tube and subsequently within thetube in the opposite flow direction to the exit. Perforated tubes may beused in alternative.

In the case of the marginal column filters it is of particular interestto achieve a certain degree of filtration as well as a relatively highfilter surface per reconstructed volume. As these marginal columnfilters consist in a number of film elements stacked on top of eachother, there is a tendency to develop these elements as thin aspossible, so as to achieve an ideal ratio between the open and closedsurfaces. In the case of very fine filters a series of additionalring-shaped elements are punched out of film which are then sometimesbroken out and which then must be stacked on the previously mentionedmetal bar. The resulting filter cakes can consist for example in 6.000elements with a film thickness of 0.1 mm. Hence the lengths of thefilter cartridge can generally vary from 10 to 100 cm.

The disadvantage with this known marginal column filter is that aconsiderable number of single film elements must be stuck on to a numberof metal bars in order to create the matrix-like arranged filtercartridges. This is technically quite complex in terms of production.

Having premised this, the purpose of the invention is to offer an easiermeans of manufacturing a filter of the aforementioned kind.

The technical solution is distinguished by the features pointed out inclaim 1.

The basic idea underlying the invention of the marginal column filterconsists in the fact that film rings are connected together in a matrixright from the beginning by means of specifically conceived connectingfillets. These matrixes are stacked in their entirety. Therefore it isno longer necessary to punch out single elements in order to processthese, but almost the complete filter block is punched out of the filmas matrix, while the elements are connected among themselves by means ofthin fillets. As a result in a single punching procedure a very bigmatrix consisting in many film elements can be made; as the latter arealready in place, the creation of large filter surfaces is considerablysimplified. Hence it is no longer necessary to punch out or collect thefilm elements. The stacking is also more effective, as the elementmatrixes can be stacked on top of each other. In addition, large filtersurfaces can be achieved with few or no metal rods as opposed to themany metal rods assigned to the filter cartridges in other procedures.The creation of an entire filter without guiding tubes is also possible.This procedure also allows for the creation of countless customizedsizes. This would not be easy to achieve if single elements wereemployed without any connection between them. As a result the filter canincrease considerably in efficiency. Furthermore the production costsfor filter systems can be considerably reduced, as the constructionsizes can be lowered; otherwise filter systems could be made much moreefficient at equal cost. Through the specific production technologysubject of this invention it is furthermore possible to create very fineconstructions and very thin film can be employed. Furthermore themicrotechnology allows for the blowing out of dirty channels between thering stacks of the film elements. In addition the clean oil conduct aswell as the regeneration channels and lastly the air channels can beincorporated into the cover plate.

Basically it can be hypothesized that partial surface areas can becreated by means of inherently stable filter matrixes. According to thedevelopment in claim 2, it is however suggested that all film elementson the same level be connected with each other by means of connectingfillets. Therefore the entire filter cross-section is formed through thestacking of appropriately dimensioned matrixes.

The development according to claim 3 suggests a special arrangement ofthe film elements as well as the connecting fillets merely as anexample. Different arrangements are conceivable for a variety ofexecution forms, for example triangular arrangements or even star-shapedarrangements.

As already mentioned, according to the development set out in claim 4the film elements as well as the connecting fillets are punched out ofone film sheet. Therefore in the case of the film matrix we are dealingwith a one-piece formation.

And lastly the development according to claim 5 suggests that the stackswith their film elements can be pressed together. This offers atechnically simple possibility of regulating the fineness of the filter.As a consequence the filtering strength can be modified by means ofregulating the pressure on the matrix stack.

An example of execution of the filter object of the invention issubsequently described by means of the drawings. These show:

FIG. 1 a view of a matrix of film elements

FIG. 2 a view in perspective of the filter with matrixes stacked on topof each other

FIG. 3 a cross-section through the filter with the additionalpossibility of regulating the filter strength

FIG. 1 shows a number of round film elements 1, which each display aconcentric equally round perforation 2. These film elements 1 areconnected by means of connecting fillets 3. The entire formation as itis illustrated in FIG. 1 is punched out of one film sheet.

FIG. 2 shows that a number of these matrixes of film elements 1connected by means of connecting fillets 3 are stacked on top of eachother. The thickness of the film is shown here in a slightly exaggeratedway. Depending on the number of film elements 1 per matrix, acorresponding number of stacks 4 are formed. Any kind of centering orfixing device for the matrixes is not explicitly shown here. It couldalso be hypothesized that a metal rod could be running through the filmelements 1 in the four corner points of the matrix.

Lastly, FIG. 3 shows in a schematic cross-section illustration, that thelower side and the upper side of the stacks 4 are formed by a base plate5 as well as a cover plate 6. Between these two plates 5,6 a preloadingdevice 7 is provided for. In addition the base plate 5 is equipped withguiding channels 8 for the dirty phase, and the cover plate 6 isequipped with guiding channels 9 for the filtered phase. The cover plate6 is also outfitted with an outlet for the cleaned fluid.

The method of functioning is as follows:

The fluid to be cleaned is fed to the filter by flowing externallyaround the stacks 4. This is indicated by the arrows P1. The fluid flowsfrom the outside through the intermediate spaces between the layers. Thesubstances to be filtered out are deposited on the outside of the stack4 of the film elements 1 as a so-called filter cake. The fluid cleanedin this manner flows into the channel 11 formed by the perforations 2 ofthe film elements 1 and flows out as cleaned fluid. This is indicated bythe arrows P2.

By operating the preloading device 7 the pressure on the film elements 1can be modified, thus regulating the fineness of the filtering process.

1-5. (canceled)
 6. A filter for phase separation, comprising: aplurality of film elements stacked on top of each other showing centralperforations aligned with each other, whereby several stacks arearranged in parallel as well as matrix-like fashion to each other, whilefilm elements of neighboring stacks lie on a common level connected toeach other by means of connecting fillets, and whereby the phase to befiltered flows from the outside through spaces in between neighboringfilm elements and the filtered phase flows out through channels formedby means of the central perforations; a base plate and a cover plate,between which the stacks with the film elements are arranged anddistinguished by means of the base plate, showing guiding channelsaligned with the perforations of the film elements for the soiled phase,and that the cover plate shows guiding channels for the filtered phaseas well as an outlet for the clean phase and air channels for the aircleaning of the dirty channels between the ring stacks of the filmelements; and a preloading device is provided for between the base plateand cover plate, by means of which the pressure on the stacks with theirfilm elements can be regulated.
 7. The filter according to one of theprevious claims, wherein all the film elements lying on the same levelbeing connected to each other by means of connecting fillets.
 8. Thefilter according to one of the previous claims, is distinguished, by thefilm elements lying on the cutting points of the grid lines, and theconnecting fillets on the grid lines of a rectangular, particularlysquare grid net.
 9. The filter according to one of the previous claims,is distinguished, by the film elements as well as the connecting filletsbeing punched out of a single sheet of film.